linux.git/net/sctp/outqueue.c, branch v4.15

sctp: avoid compiler warning on implicit fallthru

2018-01-15T18:56:13+00:00

These fall-through are expected.

Signed-off-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Reviewed-by: Xin Long 
Signed-off-by: David S. Miller

sctp: do not abandon the other frags in unsent outq if one msg has outstanding frags

2017-12-01T20:06:24+00:00

Now for the abandoned chunks in unsent outq, it would just free the chunks.
Because no tsn is assigned to them yet, there's no need to send fwd tsn to
peer, unlike for the abandoned chunks in sent outq.

The problem is when parts of the msg have been sent and the other frags
are still in unsent outq, if they are abandoned/dropped, the peer would
never get this msg reassembled.

So these frags in unsent outq can't be dropped if this msg already has
outstanding frags.

This patch does the check in sctp_chunk_abandoned and
sctp_prsctp_prune_unsent.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: abandon the whole msg if one part of a fragmented message is abandoned

2017-12-01T20:06:24+00:00

As rfc3758#section-3.1 demands:

   A3) When a TSN is "abandoned", if it is part of a fragmented message,
       all other TSN's within that fragmented message MUST be abandoned
       at the same time.

Besides, if it couldn't handle this, the rest frags would never get
assembled in peer side.

This patch supports it by adding abandoned flag in sctp_datamsg, when
one chunk is being abandoned, set chunk->msg->abandoned as well. Next
time when checking for abandoned, go checking chunk->msg->abandoned
first.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: only update outstanding_bytes for transmitted queue when doing prsctp_prune

2017-12-01T20:06:23+00:00

Now outstanding_bytes is only increased when appending chunks into one
packet and sending it at 1st time, while decreased when it is about to
move into retransmit queue. It means outstanding_bytes value is already
decreased for all chunks in retransmit queue.

However sctp_prsctp_prune_sent is a common function to check the chunks
in both transmitted and retransmit queue, it decrease outstanding_bytes
when moving a chunk into abandoned queue from either of them.

It could cause outstanding_bytes underflow, as it also decreases it's
value for the chunks in retransmit queue.

This patch fixes it by only updating outstanding_bytes for transmitted
queue when pruning queues for prsctp prio policy, the same fix is also
needed in sctp_check_transmitted.

Fixes: 8dbdf1f5b09c ("sctp: implement prsctp PRIO policy")
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: introduce stream scheduler foundations

2017-10-03T23:27:29+00:00

This patch introduces the hooks necessary to do stream scheduling, as
per RFC Draft ndata.  It also introduces the first scheduler, which is
what we do today but now factored out: first come first served (FCFS).

With stream scheduling now we have to track which chunk was enqueued on
which stream and be able to select another other than the in front of
the main outqueue. So we introduce a list on sctp_stream_out_ext
structure for this purpose.

We reuse sctp_chunk->transmitted_list space for the list above, as the
chunk cannot belong to the two lists at the same time. By using the
union in there, we can have distinct names for these moments.

sctp_sched_ops are the operations expected to be implemented by each
scheduler. The dequeueing is a bit particular to this implementation but
it is to match how we dequeue packets today. We first dequeue and then
check if it fits the packet and if not, we requeue it at head. Thus why
we don't have a peek operation but have dequeue_done instead, which is
called once the chunk can be safely considered as transmitted.

The check removed from sctp_outq_flush is now performed by
sctp_stream_outq_migrate, which is only called during assoc setup.
(sctp_sendmsg() also checks for it)

The only operation that is foreseen but not yet added here is a way to
signalize that a new packet is starting or that the packet is done, for
round robin scheduler per packet, but is intentionally left to the
patch that actually implements it.

Support for I-DATA chunks, also described in this RFC, with user message
interleaving is straightforward as it just requires the schedulers to
probe for the feature and ignore datamsg boundaries when dequeueing.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13
Tested-by: Xin Long 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: introduce struct sctp_stream_out_ext

2017-10-03T23:27:28+00:00

With the stream schedulers, sctp_stream_out will become too big to be
allocated by kmalloc and as we need to allocate with BH disabled, we
cannot use __vmalloc in sctp_stream_init().

This patch moves out the stats from sctp_stream_out to
sctp_stream_out_ext, which will be allocated only when the application
tries to sendmsg something on it.

Just the introduction of sctp_stream_out_ext would already fix the issue
described above by splitting the allocation in two. Moving the stats
to it also reduces the pressure on the allocator as we will ask for less
memory atomically when creating the socket and we will use GFP_KERNEL
later.

Then, for stream schedulers, we will just use sctp_stream_out_ext.

Tested-by: Xin Long 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: remove the typedef sctp_xmit_t

2017-08-07T04:33:42+00:00

This patch is to remove the typedef sctp_xmit_t, and
replace with enum sctp_xmit in the places where it's
using this typedef.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: remove the typedef sctp_retransmit_reason_t

2017-08-07T04:33:41+00:00

This patch is to remove the typedef sctp_retransmit_reason_t, and
replace with enum sctp_retransmit_reason in the places where it's
using this typedef.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: remove the typedef sctp_sack_variable_t

2017-07-24T23:01:20+00:00

This patch is to remove the typedef sctp_sack_variable_t, and
replace with union sctp_sack_variable in the places where it's
using this typedef.

It is also to fix some indents in sctp_acked().

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

net: convert sk_buff.users from atomic_t to refcount_t

2017-07-01T14:39:07+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller